please, how to accelerate both spindles, after clamping the same part ?

hello :) please, on a dual spindle lathe, a part is being clamped in both spindles

how to accelerate both in sync, from 0 rpm ? kindly :)

Sync with M151, clamp, M3.

Is this a trick question - you know how to do this.

hy mr wizard :) error that i received, was about not possible to sync with both chucks clamped

during the weekend, i searched the forum a bit, and i found M883, that i will test later; i searched infos for it into manuals: i find only one reference, inside the alarm&error manual

also, i found your explanation about posibility to twist the bar if both chucks are clamping; now i am wondering if, by using M883, and if it will work, then both chucks will accelerate in sync all the way up, like from 0 rpm, or will they start to sync after a slow rpm, like each one going randomly towards 20rpm, then sync

is not a tricky question: i have programed dual spindles on gang lathes, and transfer on okuma, but not this kind of situation :)

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there is a part in the chuck, i mount over it another part like a flange, and then i push with the 2nd spindle, in order to avoid fly-out; what happened, so far, is that if 2nd spindle isn't pushing hard enough, then:
... when main spindle accelerates, 2nd one will follow with a delay
... when machining, the flange simply stops from rotating, together with the 2nd spindle, while main one is still going; thus thrust generated from 2nd spindle can not overcome the momentum created by the cutting tool; to overcome this, i have also lower doc; diameter is arround 270, so is not like machining a small diameter
* in both cases, marks appear on the parts

even if i use torque skip on 2nd spindle, it looses it's thrust fast, as it can not maintain is pushing for the whole period of machining, so, after g28, i simply moved it a bit more, like 0.002-0.003

i finished machining those parts, but i look for a method to do it better, because what i did, i was simply lucky that it worked :) i have to be able to accelerate with both spindles clamped, while what i did, is simply spin the 2nd spindle with the main spindle, and that worked because i have had a g28 before the S command; and later g28 started to loose thrust ... kindly :)

Ok so you want to sync with both chucks clamped but not on shaft so torque fight doesn’t occur. This is possible maybe with M883 on newer machines but it’s also possible on older machines.
First load and clamp both parts.
Use system variable VCHIO to change from OD to ID chucking on one chuck.
M151. (Opposite spindle will sync to orientation angle for transfer)
Use VCHIO to set back to OD chucking.
Start spindles rotation by G97 M03 S500 command.

As long as you don’t reset or switch modes, M151 remains active. You can even stop, jog spindles, restart and spindles remain synced.

Best regards,

Hi deadlykitten

Maybe you must use M210 M151 in same line

thank you guys :) i will test those sugestions

mr wizard, for this instance, i can avoid torque fight by synching before g22, but what if i have to clamp a long heavy shaft : is it possible to sync, whatever spindle's initial phase is ? or i should sync the empty chucks, then clamp the long part without hitting reset ( i think this is what you mean by "Sync with M151, clamp, M3") ? kindly :)

hello, seems that on p300 is only possible to read vchio, not also to write it

finally, i got this :

Code:

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    G140 ( works also for 141 )


    G50 S2000


    M83 M248 M151 M210 M883
    G97 S567 M03
    M05
    M84 M249 M64


M02

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please consider attached parameter